CS 211 - 10/21/16

Linked Lists in Java

Typically 2 classes are used

   one class for the nodes in the list

   one class for the list itself


//  must be in the file Node.java
public class Node

===========================

//  could exist in a file not named Node.java
//    often the Node class is put into a List.java file
class Node
{
  private   Integer  elem;
  private   Node next;

  //  getters and setters
  public int getElem ()
  {
     return elem;
  }

  public void setElem (int e)
  {
     elem = e;
  }

    public Node getNext ()
  {
     return next;
  }

  public void setNext (Node n)
  {
     next = n;
  }

  // constructor
  Node (int e, Node n)
  {
     elem = e;
     next = n;
  }

  Node ()
  {
     elem = -999;
     next = null;
  }
}


public class List
{
  Node head;

  List ()
  {
    head = null;
  }

  public void addToFront( int val)
  {
    Node temp = new Node (val, head );
    head = temp;
  }

}

============================
// code that uses the List class

...main( ....)
{
  // java style
  List l1 = new List();
  l1.addToFront( 5 );


  // C-style requires the user understand how the Node 
  //    class is meant to be implemented
  Node n1 = null;